Whether and how you import classes has exactly zero effect at runtime.  Imports
(with or without wildcards) are only a kind of abbreviation provided by the
compiler to save us the effort of typing in fully-qualified type names every
time.

In theory explicit importing should make compilation faster -- by a very tiny
amount.  I've never heard anyone claim that they've even managed to measure a
difference let alone found a case where it made a practical difference.

So the question comes down to how to write your code for maximum clarity.  One
school of thought asserts that you should always import each class explicitly
(rather than by a wildcard).  There's a fair consensus on that point -- with
which I disagree.  For some reason, the advocates of that point of view seem to
exclude classes in the java.lang package.  I agree entirely that it would be
counter-productive to be explicit about importing those classes -- I just
extend the logic to other well-known packages where they fail to do so ;-)

Still, that /is/ the consensus, so -- unless you prize "best practice" over
"common practice" (and there are arguments to be made for both positions) --
you won't go /too/ far wrong by falling in with the crowd, and your life may be
a little easier.

   -- chris

No.

No.

Are you that easy to convince? I have that lovely bridge on sale ... ;-)

/Thomas

It's up to you really. Different people have different styles. As far
as I know, importing in groups won't slow it down or make it larger but
it does make it less obvious to anyone else who reads your code as to
exactly which classes the methods you've used have come from.